Inheritance Subtleties?

As far as I can tell, the following do exactly the same thing:

Code:

---

function House(location, cost) {
        this.location = location;
        this.cost = cost;
        }

function Mansion(location, cost, size) {
        this.parent = House;
        this.parent(location, cost);
        this.size = size;
        }

---

Code:

---

function House(location, cost) {
        this.location = location;
        this.cost = cost;
        }

function Mansion(location, cost, size) {
        House.call(this, location, cost);        //Or similarly with apply()
        this.size = size;
        }

---

Are there any differences whatsoever? If so, which technique is better?

Nope, no differences at all (other than the obvious, that the latter creates a parent property).